Variable output air conditioning unit and control arrangement therefor



CONDITIONING UNIT AND CONTROL ARRANGEMENT THEREFOR Filed Sept 16, 1960W. G. SPIEGELHALTER VARIABLE OUTPUT AIR Nov. 21, 1961 H \S ATTORNEYStates Patent Ofiice 3,009,332 VARIABLE (BUTPUT AIR CONDITIONING UNITAND CONTRDL ARRANGEMENT THEREFOR William G. Spiegelhalter, Louisville,Ky., assignor to General Electric Company, a corporation of New YorkFiled Sept. 16, 1960, Ser. No. 56,383 8 Claims. (Cl. 62-480) The presentinvention relates to an air conditioning unit of the type adapted forcooling a room and more particularly to an improved arrangement forautomatically controlling the cooling capacity of a variable output airconditioning unit according to the normal cooling requirements of aroom.

It has been noted that the cooling requirements of a room are generallygreatest whenever the light intensity of the room is relatively great.For instance, during the daylight hours when the outdoor temperature isusually greater than it is at night and the cooling requirements of theroom are therefore very great, the light intensity in the room is, inmost cases, very high because of sunlight entering the room. At night,when a room is occupied by active persons and the cooling requirementsof the room are greater than if the room were unoccupied, the lights inthe room are generally on and the light intensity is, therefore,relatively great. At night, when the lights in a room are turned off, itis generally an indication that the occupants are no longer in the roomor that the occupants have retired and are no longer active. Thus, ithas been found possible to automatically provide greater or lessercooling according to the normal load requirements of a roommerely bymaking the cooling output or capacity of an air conditioner dependentupon the light intensity of the room.

Accordingly, it is an object of the present invention to provide an airconditioner, the capacity of which is controlled by the light intensityof the room to be conditioned.

It is another object of the present invention to provide an airconditioner adapted to operate at maximum capacity when the lightintensity of the conditioned room is relatively great and at a minimumcapacity when the room is dark or the light intensity in the room isrelatively low.

A more specific object of the present invention is to provide an airconditioning unit having the operating speed of at least one of thecomponents therein controlled in accordance with the light intensity ofthe room to be conditioned.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

In accordance with the present invention, there is provided an airconditioning unit adapted for conditioning the air in a room. Mountedwithin the unit is multi-speed motor for driving one or more of thecomponents of the air conditioner, such as the compressor or the fans ofthe conditioner, in order to control the cooling output. Control means,mounted within the room to be conditioned and exposed to light withinthe room, include a light sensing device for changing the operatingspeed of the motor according to the intensity of light in the room, andthereby control the cooling output.

For a better understanding of the invention reference may be had to theaccompanying drawing in which:

FIG. 1 is a perspective view of an air conditioning unit with portionsbroken away to show some of the inner components and having a lightsensing means on one side thereof; and

FIG. 2 is an electrical circuit arrangement showing a two-speed motorfor an air conditioner and one arrangement whereby a light sensing meansmay be electrically connected into the circuit for controlling theoperation of the two-speed motor.

Referring now to FIG. 1 there is shown an air conditioner of the typecommonly known as a room air conditioner which is adapted for mountingin a window or outer wall of a room with a portion thereof extendingoutside the room and with at least one side thereof exposed to the room.The air conditioner includes a case 2 in which is mounted arefrigeration system including a compressor 3, a condenser 4 and anevaporator 5. The case is generally divided by a barrier 6 into twosections commonly referred to as the outdoor or condenser compartment 7and the indoor or evaporator compartment 8. Room air is circulatedthrough the inlet and outlet openings 9 and 10 formed in the front side11 of the casing and is circulated over the evaporator 5 in theevaporator compartment 8 for cooling the air of the room. In order tocirculate roomair through the evaporator compartment 8, the unit isprovided with a fan 12 mounted in the evaporator compartment and drivenby a motor 13 also mounted within the casing. In the embodiment of theinvention shown, the motor 13 is mounted on the barrier 6 of the unit.

It will be understood that the air conditioning unit does notnecessarily have to be one of those types commonly known as a windowmounted air conditioner and may be one of those types mounted entirelywithin the enclosure and utilizing duct means for circulating outdoorair over the condensing portion of the unit or may even have a watercooled condensing unit. The only limiting requirement with respect tothe air conditioning unit of the 7 present invention is that it have acontrol means which is exposed to the light within the room to beconditioned.

In the embodiment of the invention illustrated, the air conditioner isadapted for mounting with the side 11 exposed to the room and it isexpedient to mount the controls on this side of the air conditioner.Provided onthe front of the'unit is -a control 14 which is adapted tooperate a main switch, such as the switch 20 of FIG. 2, for energizingthe electrical components of the air conditioning unit. In many airconditioners the control knob 14 also operates the thermostat andpermits adjustment of the temperature setting for the unit as may bedesired by the occupants of the enclosure. The controls of the unitcould, however, be remote from the air conditioner as long as they werefound within the room to be conditioned.

In order to provide variable capacity, or cooling output for the unit,it is proposed that the compressor motor or the fan motor be of themulti-speed type, thereby permitting the motor to be operated at aplurality of different speeds to change the capacity of the unit. Forpur poses of explanation, the invention will be described in connectionwith a mu-lti-speed fan motor for changing the cooling output of theunit. It will be understood, however, that the compressor motor of theunit could be a multi-speed motor instead of the fan motor and that thespeed of the motor and thereby the capacity of the unit could becontrolled in precisely the same manner as to 'be hereinafter explainedwith respect to the fan motor.

In FIG. 2 there is shown a multi-speed motor designated by the generalnumeral 13a. The motor 13a is provided with a main winding 15 and anauxiliary winding 16 having connected in series therewith a capacitor 17for changing the phase of the current passing through the auxiliarywinding 16 thereby making the motor self-starting. The motor, shown inFIG. 2, is a two-speed motor and includes a third winding 18 which iselectrically connected into the windings of the motor whenever a higherspeed operation is desired. Power is supplied to the motor circuitthrough the main switch 20, which is the switch normally opera) ated bythe control knob 14- on the front of the unit. When power is suppliedthrough the switch 26', it may be directed into the motor through aswitch means or relay switch 39 movable between first and secondpositions across a pair of contacts 21 and 22. When the contact arm ofthe switch 19 is electrically connected across contact 211, or in itsfirst position, then both of the windings l3 and 15 are connected intothe motor circuit to operate the motor on high speed. When the switch 19is in its second position connected across the contact 22 only the mainwinding 15 is placed into the motor circuit, thus the speed of the motoris greatly reduced.

The operating speed of the motor 13a is controlled by a light sensitivemeans 23 including as a component of the control means mounted on thefront side 11 of the air conditioning unit. More specifically, the lightsensing means includes a photoconductive cell 23a (illustrated in FIG.2) which is adapted to conduct electricity when the cell is energized bylight of a sufficient intensity. As may be understood upon reference toFIG. 2, when main switch is closed and power is connected across themotor circuit and, when the photoconductive cell 23a is energized bylight from within the room, electricity is conducted across the cell.This causes a relay solenoid 24, or other electrically energizable meansconnected in series with the cell, to be energized and to move theswitch 19 across the contact 21. Thus, when light energizes thephoto-conductive cell 23a both windings 1S and 15 are placed into themotor circuit and the motor operates on high speed. When the lightintensity within the room is sufficiently reduced, or the lights areturned oif, there is no longer any flow of electricity through thephoto-conductive cell 23a and, consequently, through the solenoid 24which is in series with the cell. The solenoid 24 is then de-energizedand the switch 19 moves across the contact 22. Thus, when the lightwithin the room is reduced or turned oil, the switch 19 energizes themotor circuit including only the winding 15 in the motor circuit and,thus, reduces the speed of the fan motor 13a accordingly.

In order to adjust the sensitivity of the light sensing means and topermit the unit to be operated according to particular degrees of lightsensitivity, there is connected in parallel with the photo-conductivecell 23a a variable resistance 25. By adjusting the variable resistance,it is possible, to obtain greater or lesser amounts of current flowthrough the parallel resistance circuit and thereby require lesser orgreater amounts respectively of current fiow across the photo-conductivecell 23a in order to attain the current required to energize thesolenoid 24. For example, when the resistance in the resistor 25 is madegreat there will be required more electrical current flow through thecell 23a in order to energize the solenoid 24. However, when theresistance in the resistor 25 is reduced greater current flows throughthe parallel circuit including the resistor 25 thereby reducing theamount of current flow necessary through the photo-conductive cell 23ain order to energize the solenoid 24. Inasmuch as the current flowthrough the cell is a function of the light intensity sensed by thecell, it is possible to adjust the amount of current flow requiredthrough the cell and, thereby, the degree of light intensity in the roombefore the motor 13:: is operated on high speed. In most cases it isdesirable to adjust the resistance 25 so that very little light isrequired to cause the light sensing means to adjust the motor circuit sothat it operates on high speed. In such a case the unit will generallyoperate on high speed at all times except when the lights in the roomare oh completely. In the illustrated embodiment of the invention, thevariable resistance may be adjusted by any convenient means such as therotatable control knob 26 on the front of the unit.

An advantage in having the air conditioner capacity automaticallycontrolled by the light intensity of the room to be conditioned is that,when the light intensity is low and the unit is operating at lowercapacity, the noise level of the unit is also usually much lower. Whensuch a unit is utilized in a bedroom, the noise level of the unitautomatically reduces as the lights of the bedroom are turned oiithereby creating less disturbance for the sleeping occupants. This isparticularly true Where the motor having its operating speed controlledby the light sensitive means is the fan motor, inasmuch as it is the fanwhich creates most of the noise in the majority of modern day airconditioner of the room unit type. Any reduction in fan motor speedgreatly reduces the noise level of the unit.

While in accordance with the patent statutes there has been describedwhat at present is considered to be the preferred embodiment of theinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from theinvention, and it is, therefore, the aim of the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An air conditioning unit comprising a casing adapted for mountingwithin a room to be conditioned, at least one multi-speed motor mountedin said casing for operating the air conditioning components therein,control means for said air conditioning unit, said control means beingmounted within the room to be conditioned and exposed to lightconditions therein, said control means including a switch means forchanging said operating speed of said multi-speed motor and a lightsensitive means adapted to actuate said switch means to change the speedof said multi-speed motor according to the intensity of the light in theroom.

2. An air conditioning unit, comprising a casing adapted for mountingwithin a room to be conditioned with at least one side thereof exposedto the room, said casing having air inlet and outlet openings for thecirculation of air to be conditioned from the room through said unit, amulti-speed fan mounted in said casing for circulating room air throughsaid openings in said casing, switch means in said unit for changing theoperating speed of said multi-speed motor, and a light sensitive meansmounted on the side of said case exposed to the room and adapted toactuate said switch means to change the speed of said fan motoraccording to the intensity of the light in the room.

3. An air conditioning unit comprising a casing adapted for mountingwithin a room to be conditioned with at least one side thereof exposedto the room, a refrigeration system in said casing including acompressor mounted within -said casing, said casing having air inlet andoutlet openings for the circulation of air to be conditioned from theroom through said unit, a multi-speed motor also in said casing fordriving said compressor, switch means in said unit for changing theoperating speed of said multi-speed motor, and a light sensitive meansmounted on the side of said casing exposed to the room and adapted toactuate said switch means to change the speed of said multi-speed motoraccording to the intensity of light in the room whereby the capacity ofsaid air conditioner is varied according to the intensity of light inthe room.

4. An air conditioning unit comprising a casing adapted for mounting ina room to be conditioned with at least one side thereof exposed to saidroom, said casing having air inlet and outlet openings for circulationof room air through said unit, a fan for circulating room air throughsaid openings in said casing, a fan motor mounted in said casing fordriving said fan, said fan motor having a low speed operation and a highspeed operation, switch means for selectively adjusting said fan motorfrom low speed operation to high speed operation and vice versa, and alight sensitive means mounted on said side of said case exposed to theroom and adapted to actuate said fan switch means to operate said fanmotor on high speed when the light in the room is of high intensity andon low speed when the light in the room is of low intensity.

5. An air conditioning unit comprising a casing adapted for mounting ina room to be conditioned with at least one side thereof exposed to saidroom, said casing having air inlet and outlet openings for thecirculation of room air through said unit, a fan for circulating roomair through said openings in said casing, a fan motor mounted in saidcasing for driving said fan, said fan motor having a low speed operationand a high speed operation, fan switch means movable between twopositions, said switch means in said first position operating said fanmotor at low speed and in said second position operating said fan motora high speed, and a light sensitive means mounted on said side of saidcase exposed to the room and adapted to actuate said fan switch to saidfirst position when light in the room is of low intensity and to saidsecond position when light in the room is of high intensity.

6. An air conditioning unit comprising a casing adapted for mounting ina room to be conditioned with at least one side thereof exposed to saidroom, said casing having air inlet and outlet openings for circulationof room air through said unit, a fan for circulating room air throughsaid openings in said casing, a fan motor mounted in said casing fordriving said fan, a first circuit in said fan motor adapted to operatesaid fan at high speed, a second circuit in said fan motor adapted tooperate said fan motor at low speed, fan switch means movable between afirst position wherein said switch means energizes said first fan motorcircuit and a second position wherein said switch means energizes saidsecond fan motor circuit, a fan switch solenoid adapted to operate saidswitch means between said first and sec ond positions, a light sensitivemeans mounted on said side of said case exposed to light from withinsaid room, said light sensitive means including a photo-electric cellconnected in series with said solenoid means and adapted to energizesaid solenoid to move said switch means into said first position whensaid photo-electric cell is exposed to light from said room, and avariable resistor electrically connected in parallel with saidphoto-electric cell and in series with said relay solenoid, saidvariable resistor including means for adjusting the amount of resistanceand thereby the current fiow through said resistor thereby to adjust theamount of current fiow required through said photo-electric cell toenergize said fan switch solenoid.

7. An air conditioning unit comprising a casing adapted for mounting ina room to be conditioned with at least one side thereof exposed to saidroom, said casing having air inlet and outlet openings for circulationof room air through said unit, a fan for circulating room air throughsaid openings in said casing, a refrigeration system in said casingincluding a compressor, at least one motor mounted in said casing fordriving said fan and said compressor, a first circuit in said motoradapted to operate said motor at a first speed, a second circuit in saidmotor adapted to operate said motor at a lower speed than when saidmotor is operated by said first circuit, switch means movable between afirst position wherein said switchmeans energizes said first motorcircuit and a second position wherein said switch means energizes saidsecond motor circuit, a switch solenoid adapted to operate said switchmeans between said first and second positions, a light sensitive meansmounted on said side of said case exposed to light from within saidroom, said light sensitive means including a photoelectrical cellconnected in series with said solenoid means and adapted to energizesaid solenoid to move said switch means into said first position whensaid photoelectric cell is exposed to high intensity light from saidroom and to move said switch means into said second position when saidphoto-electric cell is exposed to low intensity light in said room sothat said motor is operated on high speed when the light in said room isof high intensity and on low speed when the light in said room is of lowintensity.

8. An air conditioning unit for conditioning the air within a roomcomprising a refrigeration system including a heat exchanger and acompressor, air circulating means for circulating air from said roomover said heat exchanger for conditioning said air, at least one motorfor driving said air circulating means and said compressor, at least twoseparate circuits in said motor adapted to operate said motor atdifferent speeds, switch means movable to at least two diiferentpositions wherein said switch means energizes said separate motorcircuits adapted to operate said motor at different operating speeds,electrically energizable means adapted to operate said switch means tosaid diiferent positions, a control means for said air conditioningapparatus, said control means being mounted within said room to beconditioned and exposed to light conditions therein, said control meansincluding a photo-electric cell connected in series with saidelectrically energizable means and adapted to energize said electricalenergizable means to move said switch means into said difierentpositions according to the intensity of light in the room.

References Cited in the file of this patent UNITED STATES PATENTS1,819,439 Peterson Aug. 18, 1931 2,307,292 Palmer Jan. 5, 1943 2,339,987Evans Jan. 25, 1944 2,917,904 Davis Dec. 2 1959

